title: Iron oxide nanoparticles and magnetic field exposure promote functional recovery by attenuating free radical-induced damage in rats with spinal cord transection.
abstract: BACKGROUND
  Iron oxide nanoparticles (IONPs) can attenuate oxidative stress in a neutral pH environment in vitro. In combination with an external electromagnetic field, they can also facilitate axon regeneration. The present study demonstrates the in vivo potential of IONPs to recover functional deficits in rats with complete spinal cord injury.
  
  
  METHODS
  The spinal cord was completely transected at the T11 vertebra in male albino Wistar rats. Iron oxide nanoparticle solution (25 μg/mL) embedded in 3% agarose gel was implanted at the site of transection, which was subsequently exposed to an electromagnetic field (50 Hz, 17.96 μT for two hours daily for five weeks).
  
  
  RESULTS
  Locomotor and sensorimotor assessment as well as histological analysis demonstrated significant functional recovery and a reduction in lesion volume in rats with IONP implantation and exposure to an electromagnetic field. No collagenous scar was observed and IONPs were localized intracellularly in the immediate vicinity of the lesion. Further, in vitro experiments to explore the cytotoxic effects of IONPs showed no effect on cell survival. However, a significant decrease in H2O2-mediated oxidative stress was evident in the medium containing IONPs, indicating their free radical scavenging properties.
  
  
  CONCLUSIONS
  These novel findings indicate a therapeutic role for IONPs in spinal cord injury and other neurodegenerative disorders mediated by reactive oxygen species.
authors.affiliation: Department of Physiology, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Ajay
authors.initials: A
authors.lastname: Pal
authors.forename: Anand
authors.initials: A
authors.lastname: Singh
authors.forename: Tapas C
authors.initials: TC
authors.lastname: Nag
authors.forename: Parthaprasad
authors.initials: P
authors.lastname: Chattopadhyay
authors.forename: Rashmi
authors.initials: R
authors.lastname: Mathur
authors.forename: Suman
authors.initials: S
authors.lastname: Jain
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D055909:Magnetic Field Therapy; D058185:Magnetite Nanoparticles / Q000737:chemistry / Q000627:therapeutic use; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013119:Spinal Cord Injuries / Q000628:therapy*
chemical_list: D058185:Magnetite Nanoparticles
keywords: cytotoxicity; electromagnetic field; neurodegeneration; oxidative stress; pain; secondary damage